Pretty simple question, I noted it when worked on exfile library.
This expression returns:
is_atom(nil) # => true
It's kinda unpredictable. My question is: how it's happened? Why it returns true?
2
votes
2 Answers
8
votes
nil is an atom, along with true and false.
This is documented for true and false in http://elixir-lang.org/getting-started/basic-types.html#atoms
You can also check with:
nil == :nil
true == :true
false == :false
Some relevant links:
https://github.com/elixir-lang/elixir/blob/v1.3.2/lib/elixir/src/elixir_tokenizer.erl#L986 https://github.com/elixir-lang/elixir/blob/v1.3.2/lib/elixir/src/elixir_parser.yrl#L253
